HYAN Renovates 1970s Wooden House into Studio in Hayama

Japanese architecture firm HYAN has completed the renovation of a deteriorated 1970s wooden house in the hills of Hayama, Kanagawa, transforming it into the residence and studio of its founders. The project, named Green Sandwich House, was designed by Shohei Hasegawa with principal architect Anna Naganuma, and interior design by Haruka Shoji. The general contractor was Deguchi Tategu-ten. The house, built in the late 1970s during the development of a residential district behind the former imperial villa area of Hayama, predates Japan's 1981 seismic code. Instead of demolishing the structure, HYAN chose to inherit and renovate it, preserving a piece of architectural heritage. The project covers 271 square meters and was completed in 2025. Photographs were taken by Katsuhiro Aoki. The renovation was curated by Miwa Negoro. This approach reflects a growing trend in Japan to reuse existing buildings rather than replace them, especially those from the pre-1981 era, which are often considered vulnerable to earthquakes but hold historical value.